2007 Evinrude E-Tec 75, 90 HP outboards Service Manual, Page 48Get this manual
INSTALLATION AND PREDELIVERY OUTBOARD INSTALLATION If the standard spacing does not allow full steering travel in particular installation, it may be necessary to increase the spacing
Transom Heights
Make sure the transom height is consistent with the height of the outboard to be installed 19 to 21 in(48.3 to 53.3 cm) transom height uses 20 in(50.8 cm) shaft outboard The shaft length of the outboard being installed should come close to matching the transom height of the boatDetermine transom height by measuring from the top edge of the transom, along the centerlineFor dual-outboard installations, transom height should be measured at the outboard centerlinesUse straightedge as reference to extend the bottom of the boatPosition the straightedge along centerlineThe distance from the top edge of the straightedge to the top edge of the transom is the actual transom height1